means return to or, if that does not occur, to the beginning of the piece.
D.C. or Da Capo, literally ‘from the head’, i.e. return to the beginning.
D.S or Dal Segno, i.e. from the sign, meaning the return to the mark :S:.
A.S. (rare) or Al Segno, i.e. to the sign. Usually the expression is D.C. al Segno e poi la Coda, i.e. ‘From the beginning to the :S: and then the Coda’.
Bis means perform the passage twice.
To avoid needless writing or engraving (especially in orchestral mus.) the repetition of a short passage is often indicated as:
Sometimes when a section is marked to be repeated it ends in a way suitable for the return to the beginning, and, having been repeated, ends in a way suitable to proceed to the next section (or to close the whole composition if nothing more follows). The two endings are then shown thus:
Or instead of the ‘1’ there may be used the expression ‘1ma Volta’, or ‘Prima Volta’, or ‘1st Time’.
Instead of the ‘2’ there may be used the expression ‘2da Volta’, or ‘Seconda Volta’, or ‘2nd Time’. When a return to the opening of the piece, or of some section of it, is indicated but only a part is to be repeated and then the piece brought to an end, the word Fine (end) shows where to stop.
For instance, a minuet is often followed by another minuet called trio, after which the first minuet is to be repeated and then an end to be made. In this case the word ‘Fine’ is placed at the end of the first minuet to indicate that this is the place to conclude when performing the repetition.
"repeat marks." The Concise Oxford Dictionary of Music. . Encyclopedia.com. (November 20, 2018). https://www.encyclopedia.com/arts/dictionaries-thesauruses-pictures-and-press-releases/repeat-marks-0
"repeat marks." The Concise Oxford Dictionary of Music. . Retrieved November 20, 2018 from Encyclopedia.com: https://www.encyclopedia.com/arts/dictionaries-thesauruses-pictures-and-press-releases/repeat-marks-0
Modern Language Association
The Chicago Manual of Style
American Psychological Association
There is a ‘catch’ in (c) and (d), the convention not being quite logical. In (c) (3 examples are given) the time-value to be filled is that of one of the notes shown (in this case half-note); in (d) the time-value to be filled is that of both of the notes shown (in this case eighth notes).
Note. If tremolo (or trem.) is added to any of the above or similar signs the notes concerned should be repeated very rapidly and without any attention to the exact number of repetitions attained during the time-value available.
"repeat marks." The Concise Oxford Dictionary of Music. . Encyclopedia.com. (November 20, 2018). https://www.encyclopedia.com/arts/dictionaries-thesauruses-pictures-and-press-releases/repeat-marks
"repeat marks." The Concise Oxford Dictionary of Music. . Retrieved November 20, 2018 from Encyclopedia.com: https://www.encyclopedia.com/arts/dictionaries-thesauruses-pictures-and-press-releases/repeat-marks